Ecclesiastical, but chiefly Papal, emissaries to the Court of the Emperor were designated by this name from the fourth to the ninth century. So long as the civil power persecuted the Church, there was no place for such officials; but after the conversion of Constantine, the recognition by the Roman emperors of the divinity of Christianity and the claims of the hierarchy gave rise to numberless questions, within the borderland of the civil and the ecclesiastical jurisdiction, which it was important for the Popes to press on the notice of the emperors, and obtain definite answers upon, so that a practical adjustment might become possible. The Apocrisiarius, therefore, corresponded to the Nuncio, or Legate a latere of later times, and was usually a deacon of the Roman Church. Gregory the Great resided in this character for three years at Constantinople in the reign of the Emperor Mauricius. After the middle of the eighth century we hear no more of such an emissary, because the Adoption of the extravagances of the Iconoclasts by the imperial Court led to a breach with Rome. But when Charlemagne revived the Empire of the West, similar diplomatic relations arose between him and the Holy See, which again required the appointment of Apocrisiarii. It appears that under the first Frankish emperors the imperial arch-chaplain was at the same time Papal Apocrisiarius. Subsequently the name was given to officials of Court nomination, who held no commission from Rome; and in this way the title in its old sense came to be disused, and was replaced by Legatus, or Nuntius.